Because it is this small, its focal length is only 18 metres.

因为它体积偏小，所以它的聚焦只有18米。

Some are capable of changing focal length, while others keep the image sharp at all times or offer 360-degree vision.

一些相机能够改变焦距, 而另一些则能够时刻保持图像清晰或提供360度的视野。

And then if there are new things that could be implemented in there, and using focal length in a certain way.

然后，我还会思考在这个地方能不能有一个新点子, 并以某种方式使用焦距。

But the focal length doesn't really have anything to do with getting this kind of distortion.

但是焦距与获得这种失真并没有任何关系。

It’s the equation that relates the object distance and the image distance to the lens’s focal length.

这是将物距和像距与镜头焦距联系起来的方程式。

The role focal length plays is just framing the scene to keep the subject the same size.

焦距的作用只是构图场景以保持主体大小相同。

You get maximum magnification when the real image is just barely inside the focal length of the eyepiece. .

当真实图像刚好在目镜焦距内时，您将获得最大放大倍率。

The next step is to focus all of the visible spectrum into the same focal length using a meta-surface lens.

下一步是使用超表面透镜将所有可见光谱聚焦到相同的焦距。

It's the equation that relates the object distance and the image distance to the lens's focal length.

这是将物距 和像距与镜头焦距联系起来的方程式。

And one measure of a lens is its power, which is expressed simply as one over the focal length.

镜头的衡量标准是它的光焦度，它简单地表示为-焦距上的一个-。

Since the new Photonic Engine now uses a 48-megapixel image, iPhone can shoot higher resolution photos in 24, 28, and 35-millimeter focal length.

由于新的光子引擎现在使用 48 兆像素的图像，iPhone 可以在 24、28 和 35 毫米焦距下拍摄更高分辨率的照片。

And if you're a camera operator, focal length is the thing you’re going to think about because you probably already know about walking.

如果您是摄像师， 焦距是您要考虑的因素，因为您可能已经了解步行。

For a single converging lens, the focal length and the object distance will always be positive.

对于单个会聚透镜，焦距 并且身体距离将始终为正。

You can see there start smoking immediately that's incredible the focal length of the lens is the place where [all] of the light converges?

您可以看到那里立即开始冒烟，这真是令人难以置信，镜头的焦距是 [所有] 光线汇聚的地方？

For a diverging lens, the thin lens equation is still true, but the focal length is now a negative value.

对于间隔透镜，薄透镜方程仍然是 正确，但现在的焦距是 负值。

When you change your the focal length by changing your lens or zooming in, a zoom lens is just a lens that can change focal lengths.

当您通过更换镜头或放大来改变焦距时，变焦镜头只是可以改变焦距的镜头。

For iPhone 15 Pro Max, we're using the extra size of the larger iPhone to introduce something unique: 4x optical zoom at 120-millimeter focal length.

对于 iPhone 15 Pro Max，我们利用较大 iPhone 的额外尺寸来引入一些独特的功能：120 毫米焦距下的 4 倍光学变焦。

Using your small-angle approximation, you can then replace the angles in the magnification equation with the new expressions in terms of image height and focal lengths.

使用您的小角度近似，您可以将放大方程中的角度替换为图像高度和焦距方面的新表达式。

The lens in your eye is controlled by muscles that change the focal length in order to focus on objects at varying distances.

眼睛中的晶状体由 改变焦距的肌肉控制，以便聚焦 不同距离的物体。

That works because you’ve taken a bunch of incoming parallel rays, and placed your target of choice at the focal length of the magnifying glass.

这是可行的，因为您已经拍摄了一束入射的平行光线，并将您选择的目标放在放大镜的焦距处。